Richard Bejtlich's blog on digital security, strategic thought, and military history.

Saturday, July 26, 2008

Review of Nmap Network Scanning

Recently Fyodor sent me a pre-publication review copy of his new self-published book Nmap Network Scanning (NNS). I had heard of Fyodor's book when I wrote my review of Nmap in the Enterprise last month, but I wasn't consciously considering what could be in Fyodor's version compared to the Syngress title. Although the copy I read was labelled "Pre-Release Beta Version," I was very impressed by this book. In short, if you are looking for the book on Nmap, the search is over: NNS is a winner.

I've reviewed dedicated "tool" books before, including titles about Snort, Nessus, and Nagios. NNS dives into the internals of Nmap unlike any other title I've read. Without Nmap author Fyodor as the author, I think any competitor would need to have thoroughly read the source code of the application to have a chance at duplicating the level of detail Fyodor includes in NNS. Instead of just describing how to use Nmap, Fyodor explains how Nmap works. Going even further, he describes the algorithms used to implement various tests, and why he chose those approaches. The "Idle Scan Implementation Algorithsm" section in Ch 5 is a great example of this sort of material. I will probably just refer students of my TCP/IP Weapons School class to this part of NNS when we discuss the technique!

One of the best parts of NNS, mentioned by explained in no other text, is the Nmap Scripting Engine (NSE). Ch 9 is all about NSE, with a brief intro to Lua and excellent documentation of using and building upon NSE. Beyond this groundbreaking material readers will find many examples of Nmap case studies from users. This and other sections help make NNS a practical book, showing how people use Nmap in their environments for a variety of purposes.

NNS is a five star book, and when it's posted at Amazon.com I'll upload this review there. You can learn more about the book at nmap.org/book, and see it in paper at Def Con next month.